Resumo

LOPEZ-SANTOS, Armando; GONZALEZ-CERVANTES, Guillermo; CADENA-ZAPATA, Martín  e  GONZALEZ-BARRIOS, José Luis. Effect of primary tillage on the physical quality of soil, as evaluated by disk permeameter. Tecnol. cienc. agua [online]. 2012, vol.3, n.4, pp.127-141. ISSN 2007-2422.

The effect of primary tillage on the hydraulic conductivity and porosity of clay soil was evaluated. The experiment was conducted in the "Los Angeles" ranch, Saltillo, Coahuila, Mexico (latitude 25.1108° N & length -100.9902° O). The hydraulic conductivity (Kc) was measured in situ with a tension disc permeameter at the surface (Kc₀) and at a depth of 8 cm (Kc₈). A random design treatment for two tillage systems was used, with disk plow (LAD), multi-plow (LM) and a control (NL), and four tension moistures: -150 (T1), -100 (T2), -50 (T3) & -10 (T4) mm. The movement of water in the soil profile up to the saturation point (Ksc) was associated with porosity. Tillage was conducted in June and July 2009, and Kc was measured two months later. Based on readings of water depletion and time, instantaneous infiltration rates were calculated in cm h^-1 for Kc and Ksc. NL had the highest values of Ksc for the two levels at which measurements were made; while on the surface in LM₀, Ksc₀ had lower values; LAD₀ had the same behavior at a depth of 8 cm in T4-10. It was also noted that the functioning of macropores (> 30 μm) is expressed when the voltage is -10 mm. Ksc₀ speeds for the 4 voltage levels showed no significant difference, while for Ksc₈ the differences were highly significant (alpha = 0.05), with average speeds of 87, 37 and 54 cm h^-1 for NL, LAD, and LM, respectively.

Palavras-chave : edaphic porosity; variable head permeameter; multi-plow.